Electric motors are used for various purposes in automotive vehicles. Commonly, pulse width modulation (PWM) is used to drive the motor. A number of trade offs must be considered when determining the duty cycle of the pulse width modulation signal. System performance and NVH goals are typically at competing ends of the trade off dynamic. For example, in order to meet NVH goals, the duty cycle of the pulse width modulated signal should be low. However, the low duty cycle requires the motor to run longer and may potentially compromise the system performance. Oftentimes minimum duty cycle levels are set so that minimum performance criteria of a given system may be met. The minimum duty cycles do not allow reduced noise vibration and harshness (NVH).
It would therefore be desirable to provide a motor-driven system that is capable of operating at a reduced noise vibration and harshness level while not compromising overall system performance.